Photometric determination of nitrate. • Photometric determination with 2,6-dimethylphenol in sulphuric acid/ phosphoric acid mixture. • In acidic solution nitrate ions react with 2,6- dimethylphenol to form 4-nitro-2,6-dimethylphenol, which can be evaluated photometrically. • Type: tube test 0-64. • Range: 0.3 – 22.0 mg/l NO3-N; 2 - 100 mg/l NO3-. • Sufficient for: 20 determinations. • Sea water suitability: no.